计及直流侧大电感的MMC建模与控制  

Modeling and Control of the MMC With Consideration of Large Reactors on its DC Side

作　　者：史先强 蔡旭[1] 姚为正[2] 吕敬[1] 董鹏[1] 吴金龙 方梓熙 饶芳权 SHI Xianqiang;CAI Xu;YAO Weizheng;LYU Jing;DONG Peng;WU Jinlong;FANG Zixi;RAO Fangquan(Key Laboratory of Control of Power Transmission and Conversion,Ministry of Education(Shanghai Jiao Tong University),Minhang District,Shanghai 200240,China;Xuji Group Co.,Ltd.,Xuchang 461000,Henan Province,China;Xi’an Xuji Power Electronic Technology Co.Ltd.,Xi’an 710075,Shannxi Province,China)

机构地区：[1]电力传输与功率变换控制教育部重点实验室(上海交通大学),上海市闵行区200240 [2]许继集团有限公司,河南省许昌市461000 [3]西安许继电力电子技术有限公司,陕西省西安市710075

出　　处：《中国电机工程学报》2021年第12期4261-4274,共14页Proceedings of the CSEE

基　　金：国家重点研发计划项目(2019YFE0104800);许继集团有限公司科技项目(SGXJDQ00RXJS2001222)。

摘　　要：在直流侧串联限流电抗器的模块化多电平换流器高压直流输电系统中,对于模块化多电平换流器(modular multilevel converter,MMC)其直流侧存在一个等效大电感,传统的控制策略不能满足暂态过程中MMC直流侧电流和子模块电容电压的动态需求。针对这个问题,文章提出一种MMC内外部电流解耦控制和子模块电容能量分层平衡控制的新型控制策略。该方法将MMC桥臂电流分解成直流侧电流、交流侧电流和相间环流,实现MMC内外部电流的解耦独立控制,通过控制MMC的直流侧电流、相间环流的直流分量和正负序基频分量完成对子模块电容能量的分层平衡控制。在Matlab/Simulink仿真软件中构建计及直流侧大电感的MMC仿真模型,并进行验证。仿真结果表明,当MMC直流侧包含大电感时,所提改进建模和控制方法能显著提高其直流侧电流和子模块电容能量的暂态性能。In the MMC-HVDC transmission system with the deployment of the current limiting reactors, there is an equivalent large inductance on the DC side of the MMC. Therefore, conventional control strategies will not meet the dynamic requirements of the DC side current and the cell capacitor voltages during the transient processes. To address this problem, this paper proposed a novel control strategy for internal and external current decoupling control and cell capacitor energy hierarchical balance control of the MMC. The method decomposed the MMC arm current into DC-side current, AC-side current, and interphase circulating current to realize the decoupling and independent control of the internal and external currents of the MMC. Furthermore, by controlling the DC-side current as well as the DC component and positive and negative sequence fundamental frequency components of the interphase circulating currents, the hierarchical balance control of the cell capacitor energy was achieved. Finally, a simulation model for the MMC comprising large DC reactors was built in Matlab/Simulink for verification. The results show that the modified modeling and control strategy proposed in this paper can remarkably improve the dynamic performance of the DC-side current and the cell capacitor energy for the MMC comprising large DC reactors.

关 键 词：模块化多电平变换器 直流侧电抗器 电流解耦控制 能量分层平衡控制 暂态性能 

分 类 号：TM46[电气工程—电器]